This book presents a compendium of the current managerial accounting system, in its theoretical and methodological aspects. Internal accounting is used by companies to determine their costs and analytical results, which represent essential information for their management. As a professional reference book, oriented to educational purposes at University level, the authors hope that the text serves the purpose of being useful in terms of remembering concepts, reviewing procedures and solutions, and observing new approaches. Valid processes are addressed for all types of companies, not only industrial ones, but also commercial and service ones, with cases and solutions adapted to their characteristics. Detailed knowledge of cost formation inevitably reveals opportunities for improvement in working methods, in product design, in scheduling production operations and in the configuration of the organization itself. Nowadays, it is unquestionable that the analysis and interpretation of costs represents a powerful management tool to develop responsibility as professionals or company managers.